Threat Of North Korea Nuclear Attack 'Accelerating', U.S. Warns

The threat of nuclear attack from North Korea is increasing, US Defence Secretary Jim Mattis said on Saturday.

During a trip to South Korea, Mattis said that the the US would never accept the northern state as a nuclear power, adding that any use of military weapons would result in a “massive military response” from the White House.

Mattis has been at pains during his week-long trip to Asia to stress that diplomacy is America’s preferred course as tensions between Washington and Pyongyang remain high.

JUNG YEON-JE via Getty ImagesUS Defence Secretary Jim Mattis has said that the threat of nuclear attack from North Korea is increasing.

Mattis warned Pyongyang that its military was no match for the US-South Korean alliance, and that diplomacy was most effective “when backed by credible military force.”

“North Korea has accelerated the threat that it poses to its neighbours and the world through its illegal and unnecessary missile and nuclear weapons programs,” he said, according to the Associated Press.

“I cannot imagine a condition under which the United States would accept North Korea as a nuclear power,” Mattis added.

“Make no mistake - any attack on the United States, or our allies, will be defeated. And any use of nuclear weapons by the North will be met with a massive military response that is both effective and overwhelming,” Mattis said.

Mattis’s South Korean counterpart, Defense Minister Song Young-moo, dismissed the idea of deploying tactical nuclear weapons to the peninsula as a response to the North’s advances.

But the US-Korean alliance had the ability to respond, even in the event of a nuclear attack from the North, Song added.

KCNA KCNA / ReutersNorth Korea's leader Kim Jong Un.

Tension between North Korea and the United States has been building after a series of nuclear and missile tests by Pyongyang, as well as a series of heated exchanges between North Korean leader Kim Jong Un and President Donald Trump.

The CIA has said North Korea could be only months away from developing the ability to hit the United States with nuclear weapons, a scenario Trump has vowed to prevent.

Mattis said that Kim’s behaviour had left no room to imagine accepting Pyongyang’s nuclear status.

Trump leaves for his first trip as president to Asia next week, which will include a stop in South Korea to meet President Moon Jae-in.